Eclipses are among the most predictable events on the planet. This one was known about for many decades before it crossed the U.S. earlier Monday.

Accordingly, people had been planning eclipse road trips for weeks in advance. They piled into planes and cars and made their way to the 70-mile-wide swath of land where the total eclipse would be visible. They checked online calculators, which told them the time of totality down to the second.

And yet for all the certainty, when Americans finally stopped to look up, many were gobsmacked by what they saw. For a couple of minutes, the temperature dropped, dusk fell in midday, and the sun was replaced by a circle of wispy white light — the glow of the solar corona, which is visible only when the moon directly blocks the sun's rays.

There were gasps and cheers as the eclipse made its first appearance over Oregon in the midmorning local time. From there it swept across the nation at more than 1,000 miles per hour. In Idaho they watched from national parks and high school football fields. In western Nebraska, people gathered at Carhenge, a roadside attraction devoted to automotive mysticism. Outside Troy, Kan., somebody set off fireworks.

Patchy clouds obscured the view for some places like Nashville, Tenn., but even if the eclipse couldn't be seen, people were treated to other unworldly phenomena, such as birds retreating from the sky and crickets chirping in midday.

At 2:49 p.m. ET, the eclipse crossed Charleston, S.C., and moved out over the Atlantic, exactly as predicted. It left behind millions of Americans whose view of the world was briefly altered and, for some, forever changed.